The present invention relates to a cab-over-engine (COE) freight vehicle which has a chassis and a driver""s cab which is mounted untiltably on the chassis and situated above the vehicle""s engine, which is supported by the chassis.
Trucks may be divided into the two categories of xe2x80x9cconventional trucksxe2x80x9d and xe2x80x9cCOE trucksxe2x80x9d. Conventional trucks have their engine situated in front of the driver""s cab and covered by a traditional bonnet which incorporates portions and panels/hatches which are easy to open (pivotable aside) so that the engine is readily accessible for inspection and repair. At a given total vehicle length, however, this tandem positioning of the engine and the driver""s cab results in occupation of part of the space in the longitudinal direction of the vehicle which could otherwise be used as load space. This limits the truck""s load capacity, thereby impairing its transport economics.
To enable a larger proportion of a given total vehicle length to be used as effective load space, the trend has increasingly been towards building freight vehicles in the form of COE trucks, in which the driver""s cab is situated over the engine. Part of the portion of the vehicle""s total length which in conventional trucks is occupied by the engine and bonnet can therefore be utilised in COE trucks as load space, substantially increasing the vehicle""s load capacity and improving its transport economics.
The fact that COE trucks have their engine situated under the floor of the driver""s cab makes it necessary in practice for the cab to be tiltable forwards to enable the engine to be uncovered as necessary for servicing and repair purposes. A tiltable cab does entail, however, significant design problems due to the need for a special tilt mounting, mechanisms for locking the cab in the untilted driving position, and various devices which make the tilting movement possible and transmit motion between controls fitted in the cab (e.g. steering wheel, pedals, hand-operated controls etc.) and the front wheels, engine/gearbox, wheel brakes and other equipment mounted on the chassis. A further need is for flexible and stretchable wiring for transmitting electric current and control signals between the driver""s cab and the chassis and the equipment mounted on the chassis.
The primary problem on which the invention is based is how to eliminate entirely the aforesaid design problems arising from the driver""s cab being tiltable and at the same time provide the possibility of satisfactory access to the engine for servicing and repair, from either side of the vehicle, while still maintaining the COE truck""s xe2x80x9ccompactnessxe2x80x9d as regards the total cab/engine length.
An associated object of the invention is to provide a freight vehicle in which the wall elements which delineate the engine compartment laterally and are connected to and/or mounted on the chassis (e.g. panels, hatches etc), and other vehicle parts (e.g. steps) alongside the engine, are easy to move out of the way or aside or to open so as to provide good access to the engine from both sides of the vehicle.
In the kind of vehicle indicated in the introduction, the aforesaid problem is solved and the object achieved by the vehicle""s exhibiting the constructional features of a vehicle having a chassis with an engine on the chassis on a driver""s cab mounted above the chassis and particularly non-tiltably above the chassis. The engine is in an engine compartment on the chassis. At each lateral side of the vehicle at each lateral side of the engine compartment, there is a panel that laterally delineates the engine compartment and the panel is pivotally mounted on the chassis to pivot open. There may be a user accessible step on the outside of the panel. The panel is displaceable by outward pivoting and rearward movement in the longitudinal direction of the vehicle to allow access to the engine. A cover is pivoted to the chassis at a hinge at about the same longitudinal direction position as the door hinge. The cover closes over the panel. A control arrangement joins the cab door and the cover to swing open and closed together and accommodates relative motion between the cab door and the cover.
Each side of the vehicle thus requires at least one panel which not only delineates the engine compartment laterally but may possibly also be provided with one or more steps and is attached by means of a special panel guide mechanism or guide which enable the panel to be pivoted outwards from the vehicle""s centreline and rearwards in the longitudinal direction of the vehicle to a displaced position in which the panel no longer hinders the direct access to the engine required for carrying out engine repair or inspection/servicing.
Preferred and advantageous embodiments of the freight vehicle according to the invention may also exhibit the further features indicated by the dependent patent claims.
In cases where the freight vehicle""s chassis incorporates a frame structure in the form of a beam frame, a COE vehicle""s engine will usually be situated at least partially between the parallel frame side members, particularly if the latter extend to the forward bumper at the front of the driver""s cab.
To make access to the engine from the sides still easier in such cases, it is possible to have the frame side members ending in the region immediately to the rear of the rear of the engine. The engine is then not fitted between the frame side members but advantageously in a special arrangement which may consist of a beam structure or framework structure and which is designed to provide good access to the engine from both sides. The chassis incorporates a framework structure and a suspension arrangement supporting the engine is fastened to the forward end of the frame structure.
If the panel delineating laterally the engine compartment is provided with external steps to help the driver climb up to/down from the cab, it is often desirable that these steps be concealed behind a special cover while the vehicle is in motion, to prevent the possibility of loose material (e.g. sand, gravel or small stones) accumulating or being caught on the steps, and also to help to reduce air resistance by providing the vehicle/driver""s cab with more effective streamlining to reduce the risk of vortices that might generate resistance and cause dirt to adhere to the steps.
To ensure that the aforesaid cover which in the closed position (e.g. while the vehicle is in motion) conceals the panel which carries the steps will automatically pivot away and uncover the steps when the cab door is opened, it is advantageous to have the cab door movement initiate and control the movement of the cover. The cab door and the cover over the panel are detachably coupled so that they can be opened and closed together. There is a relative motion control absorbing arrangement between them allowing some relative movement between the cab door and the cover to compensate for cab springing and for different hinged pin positions for the door and cover.
To avoid any risk of the driver""s being hindered by the cover when he is climbing up to/down from the cab, it may be advantageous that the cab door and the associated cover be attached and to have the cover and the door of the cab being supported on respective hinge pins that are at different locations with respect to the longitudinal direction on the vehicle, and particularly with the hinge pin of the cover being situated slightly forward of the door hinged pin.
A simple and robust version of the associated control arrangement is described below.
To provide optimum access to the vehicle engine for servicing and repair, it is preferable that the panel control arrangement be such that the panel can reliably move completely clear of the aperture which the cover coupled to the cab door uncovers as the door and cover open. An advantageous displaced position for the panel is then close to and alongside the vehicle""s front wheel, with the panel xe2x80x9cparkedxe2x80x9d parallel to the outside of the wheel.
A practical version of the panel control arrangement may then exhibit, for example, a hinged pin and pivot arrangement described below.